The document describes different types of storage devices used to store data on computers. It discusses magnetic storage devices like hard drives and floppy disks which use magnets to write binary data to an iron oxide coated disk. Optical storage devices like CDs and DVDs use lasers to read and write data by detecting lands and pits on the disk's surface. The document provides details on how each type of device works, common formats and capacities, as well as newer technologies like recordable CDs and DVDs.

1. Types of Storage Devices

2. Describing Storage Devices Store data when computer is off Two processes Writing data Reading data

3. Describing Storage Devices Storage terms Media is the material storing data Storage devices manage the media Magnetic devices use a magnet Optical devices use lasers Solid-state devices have physical switches

4. Magnetic Storage Devices Most common form of storage Hard drives, floppy drives, tape All magnetic drives work the same

5. Magnetic Storage Devices Floppy Disk Hard Disk Tape

6. Magnetic Storage Devices Data storage and retrieval Media is covered with iron oxide Read/write head is a magnet Magnet writes charges on the media Positive charge is a 1 Negative charge is a 0 Magnet reads charges Drive converts charges into binary

7. Magnetic Storage Devices Data organization Disks must be formatted before use Format draws tracks on the disk Tracks is divided into sectors Amount of data a drive can read

8. Tracks and Sectors

9. Magnetic Storage Devices Finding data on disk Each track and sector is labeled Some are reserved Listing of where files are stored File Allocation Table (FAT) FAT32 NTFS Data is organized in clusters Size of data the OS handles

10. Magnetic Storage Devices Diskettes Also known as floppy disks Read with a disk drive Mylar disk Spin at 300 RPM Takes .2 second to find data 3 ½ floppy disk holds 1.44 MB

11. Magnetic Storage Devices Hard disks Primary storage device in a computer 2 or more aluminum platters Each platter has 2 sides Spin between 5,400 to 15,000 RPM Data found in 9.5 ms or less Drive capacity greater than 40 GB

12. Illustrated Hard Disk

13. Magnetic Storage Devices Removable high capacity disks Speed of hard disk Portability of floppy disk Several variants have emerged High capacity floppy disk Stores up to 750 MB of data Hot swappable hard disks Provide GB of data Connect via USB

14. Magnetic Storage Devices Tape drives Best used for Infrequently accessed data Back-up solutions Slow sequential access Capacity exceeds 200 GB

15. Optical Storage Devices CD-ROM Most software ships on a CD Read using a laser Lands, binary 1, reflect data Pits scatter data Written from the inside out CD speed is based on the original Original CD read 150 Kbps A 10 X will read 1,500 Kbps Standard CD holds 650 MB

16. Optical Storage Devices DVD-ROM Digital Video Disk Use both sides of the disk Capacities can reach 18 GB DVD players can read CDs

17. Recordable Optical Technologies CD Recordable (CD-R) Create a data or audio CD Data cannot be changed Can continue adding until full

18. Recordable Optical Technologies CD Regrettable (CD-RW) Create a reusable CD Cannot be read in all CD players Can reuse about 100 times

19. Recordable Optical Technologies Photo CD Developed by Kodak Provides for photo storage Photos added to CD until full Original pictures cannot be changed

20. Recordable Optical Technologies DVD Recordable Several different formats exist None are standardized Allows home users to create DVDs Cannot be read in all players

21. Recordable Optical Technologies DVD-RAM Allow reusing of DVD media Not standardized Cannot be read in all players